The correct answers are:
- Methylation of histone tails in chromatin can promote condensation of the chromatin.
- DNA is not transcribed when chromatin is packaged tightly in a condensed form.
- Acetylation of histone tails is a reversible process.
- Some forms of chromatin modification can be passed on to future generations of cells.
- Acetylation of histone tails in chromatin allows access to DNA for transcription.
Histone modifications are post-translational modifications of histone protein that can affect gene expression by altering chromatin structure or recruiting histone modifiers.The most common modifications are methylation, phosphorylation, acetylation and ubiquitylation. All of them affect the binding affinity between histones and DNA and thus loosening (gene activation) or tightening (gene repression) the condensed DNA.
Histone methylation is a transfer of methyl group by histone methyltransferases to lysine or arginine amino acid of protein. Effect of methylation depends on the type of protein that is modified. Demethylation is the reverse process.
Histone acetylation is the process of adding of an acetyl group(by histone acetyltransferases) to histone proteins and it can also activate or inhibit the gene expression. Deacetilation is reverse process.
Answer:
Water based fluid
Explanation:
The internal environment consists of water based fluid in which the cells of the body present. A fluid called interstitial fluid or tissue fluid bathes the cells and provides essential nutrients to the cell. The human skin has fatty layers that helps to maintain internal heat which is produced by the body when the outside environment is cold. When there is cold in the environment, people lives in warm shelters and wear warm clothes in order reduce the impact of cold environment.
Answer:
may be
the discovery of new evidence
Explanation:
Accepted theories may be modified or overturned as new evidence and perspective emerges. Scientists are likely to accept a new or modified theory if it explains everything the old theory did and more. The process of theory change may take time and involve controversy, but eventually the scientific explanation that is more accurate will be accepted.
Answer:
Particle masses are often reported as powers of 10 times this unit over c squared; ... The name of what king of Epirus inspired a term meaning a very costly victory? ... This structure's outermost cells are classified as "on‐center" or "off‐center" ... In one work about these objects, a D-flat major triad followed by a B major triad is .Explanation:
